This invention relates to a process for space-dyeing fine denier yarns. In general, the process involves wrapping fine denier yarns with a wrapper yarn before space dyeing the composite bundle of yarns, and subsequently unwrapping the fine denier yarns for further processing as individual yarns. The invention also relates to an apparatus for wrapping of fine denier yarns for space dyeing and subsequently unwrapping the fine denier yarns for further processing, an intermediate yarn product formed of bundled fine denier yarns suitable for space-dyeing in a continuous process, and an end product, fine denier yarn which results from the process carried out on the intermediate yarn product.
Continuous dye lines are typically used for space-dyed carpet yarns. Carpets are typically tufted from yarns in the 1000-3000 denier range. However, there is a large potential market for space dyed fine denier yarns to be used in end uses such as automotive upholstery. Typically the denier range for this type of space-dyed yarns is 150 to 500 denier. Some automotive upholstery fabric is spaced-dyed using a proprietary needle injection dye process. Quality problems with this process are significant and typically result in dye spot length differences between the outside of the package and the inside, or core, of the package. This can cause significant pattern repeat defects in the finished fabric. Some fabric manufactures typically back-wind 1 package, and then parallel wind the back-wound yarn with another space dye yarn just to hide the pattern repeat defects. This can require that a significant percentage of the yarn be scrapped, since a good portion of the core yarn on each package is not dyed the same shade as the rest of the package.
Five hundred denier continuous filament polyester can be space-dyed in a continuous process. However, this fine denier yarn is very fragile and can cause problems in subsequent processing, for example, trying to separate the yarn ends from the coil and get them onto a yarn package at the winder. Of course, the problem would be even greater with yarns as fine as 150 denier.
Productivity issues are also present. Applicant""s applicator, dye line and winder are set up to run at a maximum speed of 500 YPM with 48 running yarn ends. With these speeds, running 150 denier yarn would not be economically practical because of lack of productivity.
Consideration has been given to many ways to get a sufficient number of ends through the dye line so that productivity would rise to the level of commercial practicability. For example, consideration has been given to the concept of dyeing the yarn, but not coiling so that it could be wound without having to separate the yarn from the coiled form. However, if the yarn isn""t coiled or compacted in some manner there is no way to obtain adequate time for steam fixation washing, drying, and so forth.
Yarn wrapping per se is a conventional process. However, known prior art uses of this process involve wrapping a yarn to achieve a wrapped end product. To applicant""s knowledge, the prior art does not disclose the formation of an intermediate yarn product which is processed, whereupon the intermediate yarn product is disassembled into its constituent, end use parts with the wrapper yarn being sacrificed.
Therefore, it is an object of the invention to provide a process for space-dyeing fine denier yarns in a series of steps.
It is another object of the invention to provide a process for space-dyeing fine denier yarns in a continuous process.
It is another object of the invention to provide a process for space-dyeing fine denier yarns while bundled together to form a yarn of sufficient size and strength to withstand the space-dyeing processing conditions.
It is another object of the invention to provide a process for space-dyeing fine denier yarns wherein a sacrificial wrapper yarn is used to form a yarn bundle of sufficient size to be dyed in a efficient and productive manner.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a method for space-dyeing yarns, comprising the steps of wrapping a plurality of feed yarns with a sacrificial wrapper yarn to form a composite yarn bundle, space-dyeing the composite yarn bundle, removing the wrapper yarn from around the feed yarns, separating the feed yarns into individual yarns for further processing.
According to one preferred embodiment of the invention, the method includes the step of winding the composite yarn bundle onto a yarn package after the space-dyeing step.
According to another preferred embodiment of the invention, the step of removing the wrapper yarn from around the feed yarns comprises the step of unwrapping the wrapper yarn from around the feed yarns.
According to yet another preferred embodiment of the invention, the step of removing the wrapper yarn from around the feed yarns comprises the step of cutting the wrapper yarn away from the feed yarns.
A further embodiment of the method according to the invention comprises the steps of spreading the composite yarn bundle to expose the wrapper yarn in advance of the feed yarns to a blade and cutting the wrapper yarn away from the feed yarns at a point in advance of the feed yarns.
According to yet another preferred embodiment of the invention, the method includes the step of aspirating the cut wrapper yarn to remove it from the feed yarns.
According to yet another preferred embodiment of the invention, the method includes the step of winding the separated feed yarns onto individual yarn packages.
According to one preferred embodiment of the invention, the process steps are carried out in a continuous process on a single apparatus having a series of process stations.
According to another preferred embodiment of the invention, the process steps are carried out in a series of discrete steps on separate machines.
According to yet another preferred embodiment of the invention, the steps of coiling, steaming and dyeing the composite yarn bundle take place after space-dyeing and before separating the wrapper yarn from the feed yarns.
According to yet another preferred embodiment of the invention, each of the plurality of feed yarns comprises a synthetic yarn having a denier of 500 or less.
According to yet another preferred embodiment of the invention, each of the plurality of feed yarns comprises a synthetic yarn having a denier of 150 or less.
According to yet another preferred embodiment of the invention, the step of wrapping a plurality of feed yarns with a sacrificial wrapper yarn comprises the step of wrapping the feed yarns with between 2 and 10 wraps of the wrapper yarn per inch.
According to yet another preferred embodiment of the invention, the wrapper yarn comprises a yarn having a denier of between 20 and 150 denier.
According to yet another preferred embodiment of the invention, the step of space-dyeing the composite yarn bundle comprises the step of passing the composite yarn bundle through a plurality of yarn-dyeing stations, each of said yarn dyeing stations including a rotatable pattern member permitting a dye to be applied to the yarn in seriatim only when disposed in a selected angular disposition relative to said yarn bundle, each pattern member being associated with a different color dye, the speed of each member controlling the angle through which each of the members rotates during repetitive time periods so that the disposition required to permit dyeing of yarn by each color may be obtained at selected times.
According to yet another preferred embodiment of the invention, the method includes the step of coordinating the location along the yarn bundle at which each member permits dye to be applied, whereby each different color dye may be applied along different amounts of the yarn bundle and at selected locations.
According to yet another preferred embodiment of the invention, the step of space-dyeing the composite yarn bundle comprises the steps of feeding said yarn bundle in one direction through said stations, locating a dye applying means at each station for applying dye of a selected color onto said yarn bundle, locating a rotatable pattern member at each station for selectively permitting and preventing dye to be applied to said yarn bundle by the respective dye applying means, and controllably rotating each pattern member independently of the other pattern members in accordance with a pattern to selected positions to permit dye to be applied to said yarn at selected times and to prevent dye to be applied to the yarn at other times. An apparatus for space-dyeing yarns in accordance with the invention comprises a yarn-wrapping apparatus for wrapping a plurality of feed yarns with a sacrificial wrapper yarn to form a composite yarn bundle, a space-dyeing apparatus for space-dyeing the composite yarn bundle, a wrapper yarn removal apparatus for removing the wrapper yarn from around the feed yarns, and a feed yarn separating apparatus for separating the feed yarns into individual yarns for further processing.
According to yet another preferred embodiment of the invention, the invention includes a winder for winding the composite yarn bundle onto a yarn package after the space-dyeing step.
According to yet another preferred embodiment of the invention, the apparatus for removing the wrapper yarn from around the feed yarns comprises an apparatus for unwrapping the wrapper yarn from around the feed yarns.
According to yet another preferred embodiment of the invention, the apparatus for removing the wrapper yarn from around the feed yarns comprises a cutter blade for cutting the wrapper yarn away from the feed yarns.
According to yet another preferred embodiment of the invention, the apparatus for removing the wrapper yarn from around the feed yarns includes a yarn bundle spreader for spreading the composite yarn bundle to expose the wrapper yarn in advance of the feed yarns to a blade and wherein the cutter blade cuts the wrapper yarn away from the feed yarns at a point in advance of the feed yarns.
Another embodiment of the apparatus for space-dyeing yarns comprises yarn wrapping means for wrapping a plurality of feed yarns with a sacrificial wrapper yarn to form a composite yarn bundle, space-dyeing means for space-dyeing the composite yarn bundle, wrapper yarn removal means for removing the wrapper yarn from around the feed yarns; and separator means for separating the feed yarns into individual yarns for further processing.
According to one preferred embodiment of the invention, winding means are provided for winding the composite yarn bundle onto a yarn package after the space-dyeing step. m According to yet another preferred embodiment of the invention, wrapper removal means are provided for removing the wrapper yarn from around the feed yarns comprises the step of unwrapping the wrapper yarn from around the feed yarns.
According to yet another preferred embodiment of the invention, the wrapper yarn removal means comprises a cutter blade for cutting the wrapper yarn away from the feed yarns.
A composite yarn bundle for permitting space-dyeing of fine denier yarns according to the invention comprises a plurality of fine denier feed yarns integrated together in parallel configuration to form an integrated core, and a sacrificial wrapper yarn wrapped around the core to form a composite yarn bundle wherein the feed yarns are maintained in integrated condition during space-dyeing, said sacrificial wrapper adapted to be removed from around the feed yarns after space-dyeing to permit separation of the core into individual feed yarns for subsequent processing.
According to yet another preferred embodiment of the invention, each of said feed yarns is 500 denier or less.
According to yet another preferred embodiment of the invention, each of said feed yarns is 150 denier or less.
According to yet another preferred embodiment of the invention, each of said feed yarns is 50 denier or less.
According to yet another preferred embodiment of the invention, the wrapper yarn is 50 denier or less.
According to yet another preferred embodiment of the invention, the wrapper yarn is wrapped onto the core with between 2 and 10 wraps per inch.
A space-dyed, fine denier yarn according to the invention comprises a feed yarn of no more than 500 denier, a plurality of colors of dye applied to the feed yarn by moving the feed yarn past a dye-applying apparatus while integrated together with a plurality of like feed yarns by means of at least one sacrificial wrapper yarn wrapped around said feed yarns to maintain the feed yarns in their integrated condition, said wrapper yarn being removed from the feed yarn after space-dyeing.